1. Technical Field
The present invention relates to a sensing circuit, a display device and an electronic apparatus.
2. Related Art
A sensing circuit configured to detect contact with an object such as a finger or a pen is known, e.g., as disclosed in JP-A1-2007-510949. The sensing circuit of JP-A1-2007-510949 is configured to detect a change in the capacitance of a capacitor element formed by electrodes arranged on two substrates facing each other and a dielectric material such as liquid crystal filled between the electrodes, so as to detect contact with an object. Sensitivity of sensing is given as a ratio of the capacitance of the capacitor element in an ordinary state to the capacitance of the capacitor element while the object is in contact with the substrate.
Incidentally, the capacitance of a capacitor element is determined from the areas of the electrodes, the permittivity of the dielectric material, and the distance between the electrodes. An ordinary sensing circuit has a spacer arranged in edge portions of two substrates facing each other for specifying a distance between the substrates. In general, the substrates warp due to their own weights even if no object is in contact with the substrate. Thus, it is not easy for the ordinary sensing circuit to keep the distance between the electrodes constant in every portion of the substrate, and it is difficult to set the capacitance to a target value. Accordingly, the ordinary sensing circuit has a problem in that the sensitivity of sensing varies.